Abstract: A control system and method for an electric machine includes a first calculation module that receives a modified torque command and a calculated stator flux command and that generates first and second current commands and first and second voltage commands. A voltage magnitude calculation module generates a voltage magnitude based the first and second voltage commands. A reference voltage calculator module generates a reference voltage based on a DC link voltage, an angular stator velocity and the first and second current commands. A flux weakening module generates the calculated flux command based on the angular stator velocity, the reference voltage and the voltage magnitude.

Abstract: A control system for a motor including a rotor comprises a sensorless sensor module that includes a saliency-based estimator module that generates a first rotor position signal based on saliency and a back electromotive force (emf) estimator module that generates a second rotor position signal based on back emf. A selector selects the first rotor position signal for rotor speeds below a first rotor speed and the second rotor position signal for rotor speeds above the first rotor speed. A rotor position sensor senses a position of the rotor and generates a third rotor position signal. A fault detection module senses faults in the rotor position sensor and outputs the third rotor position signal when a fault is not detected and one of the first and second rotor position signals when the fault is detected. An indirect field oriented control (IFOC) system controls the motor based on a selected one of the first, second and third rotor position signals.

Abstract: A method for controlling an electric machine having current sensors for less than every phase of the electric machine includes operating a processor to perform a test to preliminarily determine whether a fault exists in one or more of the current sensors and a test to finally determine that the fault exists in the one or more current sensors. The method further includes operating the processor to utilize a state observer of the electric machine to estimate states of the electric machine, wherein the state observer is provided state input measurements from each non-faulty current sensor, if any. Measurements from the current sensor or sensors determined to be faulty are disregarded. The processor controls the electric machine utilizing results from the state observer.

Abstract: The present invention includes a method for managing processor execution time in a motor controller. The method includes receiving motor speed data, comparing the received motor speed data to predetermined motor speed ranges, determining a motor speed range based on the comparison, and modulating an inverter switching frequency of the motor controller processor based on the motor speed range. The step of receiving motor speed data may include receiving machine terminal information, processing the received machine terminal information utilizing a sensorless control algorithm, and determining motor speed data based on the processed information. The step of modulating the inverter switching frequency may include determining a modified inverter switching frequency value based on the determined motor speed range and providing the modified inverter switching frequency value to a processor control algorithm.

Abstract: A control system for an electric motor having a stator and rotor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a low speed control block to estimate the rotor angular position using stator current components operating in the controller, a high speed control block to estimate the rotor angular position using stator current components and stator flux position operating in the controller, a transition switch in the controller to vary operation between the low speed control block and the high speed control block, and where the inverter is controlled by six step operation.

Abstract: A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, a second motor speed control block in the controller detecting the back electromotive force to determine the speed and position of the electric motor, and a transition control block in said controller to vary operation between the first motor speed control block and the second motor speed control block.

Abstract: A control system includes a field oriented controller that receives a torque command and that generates phase voltages for an electric machine. A first transformation module receives stator terminal currents and generates d-axis and q-axis stationary frame currents. An open loop flux observer receives d-axis and q-axis stationary frame voltage commands and the d and q-axis stationary frame currents. The open loop flux observer includes a vector cross product calculator that generates an error signal that is proportional to an angular difference between an estimated stator flux and a computed stator flux and a proportional integral controller that generates an estimated rotor angular position based on the error signal. A second transformation module receives the d-axis and q-axis stationary frame currents and the estimated rotor angular position and generates d-axis and q-axis synchronous reference frame feedback currents that are output to the field oriented controller.

Abstract: A control system for an electric motor having a stator and rotor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a low speed control block to estimate the rotor angular position using stator current components operating in the controller, a high speed control block to estimate the rotor angular position using stator current components and stator flux position operating in the controller, a transition switch in the controller to vary operation between the low speed control block and the high speed control block, and where the inverter is controlled by six step operation.

Abstract: A method for controlling an electric machine having current sensors for less than every phase of the electric machine includes operating a processor to perform a test to preliminarily determine whether a fault exists in one or more of the current sensors and a test to finally determine that the fault exists in the one or more current sensors. The method further includes operating the processor to utilize a state observer of the electric machine to estimate states of the electric machine, wherein the state observer is provided state input measurements from each non-faulty current sensor, if any. Measurements from the current sensor or sensors determined to be faulty are disregarded. The processor controls the electric machine utilizing results from the state observer.

Abstract: A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, where the first motor speed control block includes a tuned moving average filter to determine the magnitude of high frequency current in the electric motor.

Abstract: A method of reducing loss in an interior permanent magnet drive system is provided. A current input DC link power value is calculated. The current input DC link power value is then compared with a previous input DC link power value. A change in input DC link power value is determined from this comparison. A flux decrement value is calculated. The flux decrement value is based on the change in input DC link power value. A stator current value is generated. The stator current value is based on the flux decrement value. Finally, the stator flux current is reduced, based on the stator current value.

Abstract: A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, a second motor speed control block in the controller detecting the back electromotive force to determine the speed and position of the electric motor, and a transition control block in said controller to vary operation between the first motor speed control block and the second motor speed control block.

Abstract: A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, where the first motor speed control block includes a tuned moving average filter to determine the magnitude of high frequency current in the electric motor.

Abstract: A method of reducing loss in an interior permanent magnet drive system is provided. A current input DC link power value is calculated. The current input DC link power value is then compared with a previous input DC link power value. A change in input DC link power value is determined from this comparison. A flux decrement value is calculated. The flux decrement value is based on the change in input DC link power value. A stator current value is generated. The stator current value is based on the flux decrement value. Finally, the stator flux current is reduced, based on the stator current value.